From Hard courts: real life on the professional tennis tours, by John Feinstein:

Arantxa Sanchez had been having an inconsistent year, and few people gave her much chance to defend her title. But even fewer people thought that Mercedes Paz, her doubles partner, would be the person to knock her out of the tournament.

Paz was a month shy of twenty-four and had been on tour for six years. People said she could really be a factor if she ever got in shape, but at the end of 1989 she weighed 184 pounds. Even at five feet ten, that was a lot of weight to be carrying. She had finally gotten herself on a training regimen at the start of the year and had lost twenty-five pounds. She was still bulky and lacked quickness, but the difference in her game was evident.

Sanchez, meanwhile, was going through a difficult time. She had changed coaches earlier in the year, hiring Mike Estep to replace her longtime coach, Juan Nunez. Estep had a simple philosophy when it came to coaching women: anybody can attack if they want to; he had made Martina Navratilova more aggressive when he began coaching her in 1983, getting her to come in behind her second serve, and he had preached the same kind of game to every player he had worked since then.
At forty-one, Estep was thinking it might be time to get off the tennis merry-go-round. But IMG had called to say Sanchez was looking for a coach. They were willing to meet Estep’s financial terms – which included first-class airfare for him and his wife Barbara – and wanted him to meet with Sanchez. he did, liked her and her family, and took the job. Right now, though, Sanchez was caught in the middle. Part of her understood why Estep wanted her to be more aggressive, but a major part of her still felt more comfortable hugging the baseline. An indecisive player is almost always a losing player.

“What you can say?” Sanchez said in her fractured English after the match. “Last year I win there; this year, I don’t. It happens.”